Summarising field in a group header to exclude suppressed values

Hi

I have a report which shows order values in a group header. The group is suppressed when an order has been completely delivered.
When i add a summary of the order value to the report footer it is showing the total for all orders, and i only want it to show the values which appear in the group header (ie those not suppressed).

I have attached the report with some saved data. It is the order value shown in group header 3 i am trying to summarise. You can see the problem i have on the preview page

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1. Use a running total that evaluates when the order has NOT been delivered
2. Create a formula like this and summarize it
If Not {Delivered} then
{Amount}
3. Use the selection filter to select only those records that aren't delivered
4. Use formulas with variables to evaluate the total

The issue i have is that I am trying to summarise a field which depends on a summary for it's suppression conditon. I have attempted to attach the report again as that best illustrates the issue.Order-Bank-5.rpt